1. Field of the Invention
The present invention relates to a method for manufacturing a wiring board to which a semiconductor chip is to be connected, including a decoupling capacitor for the semiconductor chip.
2. Description of the Related Art
In recent years, with the reduction of the size and thickness of semiconductor devices, such as semiconductor chips, a demand for reducing the size and thickness of decoupling capacitors has been growing. Decoupling capacitors (also called decoupling condensers or bypass condensers) are used for reducing voltage variations of semiconductor chips and stabilizing operations thereof.
The operating frequency of semiconductor chips is expected to be increased for improving the operation speed of the semiconductor chips. In such circumstances, decoupling capacitors are preferably arranged near semiconductor chips so as to lower the inductance due to connection of decoupling capacitors.
To meet such preferences, various decoupling capacitors and methods for arranging a decoupling capacitor are suggested.
For example, Patent Document 1 discloses a method that mounts a semiconductor chip on a wiring board, and mounts a decoupling capacitor on a backside of the wiring board (the side opposite to the side on which the semiconductor chip is mounted). Patent Documents 2-4 disclose a structure wherein a decoupling capacitor is embedded in a wiring board.
[Patent Document 1] Japanese Patent Laid-Open Publication No. 2003-264253
[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-14573
[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-152883
[Patent Document 4] Japanese Patent Laid-Open Publication No. 2004-281830
However, in the case where a decoupling capacitor is embedded in a wiring board on which a semiconductor chip is mounted, a wiring structure between the semiconductor chip and the decoupling capacitor might cause a problem.
For example, if minute wiring members are used for connecting a decoupling capacitor to a semiconductor chip, electrodes of the decoupling capacitor might not be securely connected to the wiring members. Therefore, it is difficult to secure the connection while lowering the impedance.